Light signal



W. B. WELLS LIGHT SIGNAL Filed March 7, 19,41

2 Sheets-Sheet l INVENTOR H15t ATToRNEY Nov. 9, 1943. W.A B. WELLS 2,333,967

LIGHT SIGNAL Filed March 7, 1941 2 Sheets-Sheet 2 INVENTOR HIS ATTORNEY M252@ BYQ -W-a Patented Nov. 9, 1943 LIGHT SIGNAL Wesley B. Wells, Wilkinsburg, Pa., assigner to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application March 7, 1941, serial No. 332,193

s claims. l (ci. ivi-329) My invention relates to light signals, and particularly to searchlight signals which are capable of selectively projecting a plurality of beams of light of diiferent colors from a single light source.

In one form of searchlight signal commonly used on railroads, such for example, as that disclosed in my prior Patent No. 2,230,853, granted on February 4, 1941, for Light signals, the'signal includes a lens system for projecting a beam of parallel rays of light rigidly secured to a signal case in advance of an opening formed in the forward wall of the case, a light projecting unit detachably secured within the case and including a reflector having conjugate foci one of which is disposed at the light source and the other of which coincides with the focal point or' the lens unit, and an operating unit rigidly secured within the signal case and including a spectacle arm carrying a plurality of color filters and a motor element for selectively moving the spectacle arm to diiferent positions in each of which a different one of the color lters is interposed in the beam from the light unit at the common focal point of the light and lens units. The operating unit also includes contact mechanism operated by the mo- I shal1 describe one form of light signal embodying my invention, and shall then point out the novel yfeatures thereof in claims.

In the accompanying drawings, Fig. 1 is a Ver- A tical sectional view showing one form of light signal embodying my invention. Fig. 2 is a rear elevational View of the signal shown in Fig. 1, a portion of the door being broken away to better illustrate the construction of the parts. Figs. 3 and 4 are perspective views of certain parts of the signal shown in Figs. 1 and 2.

Similar reference characters refer to similar parts in each of the several views.

Referring rst to Figs. 1 and 2, the light signal in the form here shown comprises a box-like casing I, the forward Wall la of which is provided with a large circular opening Ib through which the light rays from a light unit A disposed inside of the casing are adapted to be projected. Secured to the forward wall la directly in front of the opening Ib by means of four screws 3 spaced 90 apart is a lens unit L for concentrat- 1 ing the light rays emitted by the light unit A into tor element for controlling similar signals, relays, f

or other apparatus. The signals are sometimes mounted in locations where they are subjected to severe vibration, and under certain yadverse conditions sufficient vibration has been transmitted to the operating unit to cause excessive wear on the pivots or other moving parts of the mechanism, and to at times vibrate open the back contacts. This is undesirable, and one object of my invention is the provision in a signal of the type described of improved means for mounting the operating unit in the signal case, whereby the undesirable effects of vibration are eliminated, and removal of the mechanism for inspection or repair is greatly facilitated. k. According to my invention, I take advantage of the fact that the areas of the color filters are considerably larger than the area of the light beam passing through them whereby, if the light and lens units are accurately positioned in the case, it is not necessary to have the operating unit accurately located in the case. In other words, sufficient movement of the operating unit can be permitted with reference to the case to enable the operating unit to be effectively mounted on shock absorbing supports without materially affecting the optical efficiency of the signal.

Other objects and characteristic features of my invention will become apparent as the description proceeds.

a signal beam. The lens unit L is of well-known construction and comprises a doublet consisting of two spaced lenses 4 and 5 mounted in the inner and outer ends, respectively, of a tubular casing 6, commonlyk referred to as alens barrel. The outer lens 5 bears around its edge against the bottom of an annular groove 'I which ls formed in the lens barrel, and is held in place by a ring member 8 and screws 9, a gasket of felt or the like preferably being interposed between the ring member and the edge of the lens. The inner lens 4 likewise bears at its edges against the bottom of an annular groove I0 which is formed in the inner end of the lens barrel, and is held in place by a ring member II and screws l2, a gasket of felt or the like (not shown) being interposed between the ring member and the edges of the lens. The two lenses are of the well-known plano-com veX type, and are both clear or colorless. Secured to the outer end of the lens barrel directly above the outer lens 5 is a hood I3 which performs the usual function of shielding the lens 5 from the direct rays of the sun.

The light unit A referred to hereinbefore comprises an elliptical reflector I5 mounted in a metal casing I6, and an electric lamp l1, the filament of which is located at one of the conjugate foci of the reflector I5. The rear Wall of the casing I6 is provided with three rearwardly projecting studs I8 arranged in triangular formation, only two of which are visible in the drawings, and mounted on thesey studs between compressed coil springs I9 which surround the shank portions of the studs, and nuts 20 which are adjustably screwed onto the outer ends of the studs, is a plate 2I. This plate carries a socket 22 which projects with some clearance through a hole 23 formed ln the rear wall of the casing I6, and serves as a support for the previously referred to electric lamp I1. Mounted on thastuds-JS outside` of the nuts 20 are lock nuts 324 for securing the A-nuts`20 in adjusted positions. It will be apparent that by adjusting the nuts 20 in the position ofthe lamp filament with.A respect to the reflectormay be varied, and these nuts are so adjusted-that the lament of the lamp wilhbe.locatedxactlyat the inner focal point ofzthefreectonthus er1-l1 Mspherical heads'jZBwhich fit intospherical sockets j 4"21 formed in radial-'armsprovided onthereflector housing, andrwhichfheads areheld'inrplace in believed toA be sufficient to state vthat -thesemeans Hpermit the lightunit-asa lwhole tube-removed by grasping a *handle30"seeuredv thereto andpulling the unit rearwardly; yaridf'thatfafterfthepunithas 'fbeen removedjit'can readily becsnappedback in placa ,'Thestudsi'ZS areso adjusted that 'the outer focal point 3-Iof they yreflector will: coincide f exactly withtheifoc'al vpointoi? thejlens unit L, as'ishown by. the `dash lline/s3! 4defining' the 'limits of the bearni of Jightemitted'by the larnpll. W

The lightjsignal' also-comprises a suitable oper; ating mechanism S'forchangingthe-color ofthe beam emittedby'thei signal-to provide a-plui'ality "of 'signaljndications As'here`^shown',this mechvspectacle arm"36 is iprovided*apt-itsfupper `encl with green, yellow. and red-colorfscreens'or filters .which 'align respectively mtn--twb f'windows sa and .140 Lofjclear glass according as" the jspectacle arm .occupies its .one extreme position, its other extreme ,position or an'"iritermediate l,position l V,.midwaybetween its two extreme*positions-"Only i theered, screen .4 I islshown in the drawings', but

,spectacle arms of the, type";desci'ibed' are well known, and it is'therefore deemed vto be unnecessary to'show this spectaclegarmir detail herein: The4 operating kmechanism alsoeomprisessuit ,able contactmechanism :not shownroperated by ,L the .motor means' fior. controlling 'similar signals, ..relays or othenapparatusforming'part of a comv,",pletesignal system. 'l j The operatingmechanism' is removably-secured withinthejcasing I- by mounting-means which IV shall describe presentlyyandis so positioned with Vrespect' to thefcasing thatth light rays' emitted 'by the light unit A` willpas'sthrougli the windows 39 and 40 on opposite sides of the common focal point of the light and lens units and will pass through that color screen which happens to be in alignment with the windows `39 and 40 sub- 5 stantially at the common yfocal point of the light and lens units,.in the manner indicated by the` dot and dash lines 32. It will be apparent, thereyfore,that the signal will .display a green, red or t .yelw'aspect accordinggas theyspectacle arm 36 10 occupies its one extreme position, its intermeg diate position, or its other extreme position.

. The top plate 35 of the operating mechanism is provided with suitable terminal posts for the reception of plug-connectors 4I to enable the ,signal toy be readily connected with external circuits. Heretofore, in' signals of the type described it has been customary to rigidly support the operating mechanism in the casing I. When the operating mechanism is rigidly supported in the -'--casing- I;=however,` aany*vibrationl towhich the 1 signalis subjected is: transmitted tothe operating f vmechanism;2anduunder==certain .adverse-foundif tions, such for :examplaaas when l= the'fsignal is fsupported-on a poleanrl` the :ground is frozen, or`4 when thev signall is-'us'ed onffel'evated1 roads, #the vibration transmitted-to the operatingmechanism has lbeen s'uiiciently" severe to greatly f acf l'celeratez 'wear z fofl the, pivots andz morving-v4 parts, and also to-at21times 'vibrate open tthewback :contactsiA Itis desirable to'iminimize insofar as possible the eifectszof vibrationfon the-operating mechanismfandhin accordance with my `present invention, I accomplish 'thisfresult byproviding new vandrimproved mountingwmeans `'for mountf --ing y the operating mechanism '.1 in'. Yther casing, r 'which mounting means includes suitable; shock absorbing devices for4 preventing "thevtransmisl sionof 'vibratioi from thesignal casing` to 'the 40 operating j mechanism, Aand which at l'the Asame -time permits the {operatingf'mecha'nismto be `removed from the casingJ for `inspection fand refpairf more :readily-y andlmorey quickly"than=has 1 heretofore?beei'r'possible.'j Thismou'nting means is made practicable "by the fact"rv that Jtheifcolor 1^screens carried f'by"-1the Aspectacle `Varm' aref cone siderably'- larger 1 in diameter than* thefarea of the :sig-nal r`beam A' where it vpasses l through "the A `color screensfandfsince'the other optical parts "ofthe signalfarellacctn'ately positioned lWithin TIAthe :casing |,-1t is notv necessary toA have-"the operating mechanism ffrigidly held uin place in Y the rsignal casing. Thatiis to fsaygsome movement fof `the operating-iriechan'lsm .can 'be per- -mitted--with vreference `to-'the v'casing I without 'aifecting f f signal. l

"" The mountingmeans embodyngr-my present thefopticalefciency*obtainedf'fromthe f inventionl comprises atrack assembly Vattached f porting-brackets'lif andfil. *Tha-front yerosslpiece 41- is.A disposed above the `sidelrailslli and i1 46; while the `rear `crosspiec 4& is disposed' below Y `thesiderailsfor a purposeY--whichfwill appear f hereinafter. l

any suitable construction,butamsaheretshuwn they are of the rubber shear type, and each comprises a rectangularv metal plate 49a. (see Fig. 1) provided withfa central hole 49h through which a cylindrical block yof rubber 49e extends. The rubber block projects outwardly past the inner edge ofthe plate 49a above and below they plate and is bonded to the plate at itsrcontiguous portions. Each support 49 alsoincludes a metal sleeve 49d which extends through the center of the rubber block and is bonded to the contiguous portions of-the block. Each sleeve 49d extends above the block for some distance for a purpose which will appear hereinafter.

The plates 49a. of the supports 49 are riveted to the associated bracket 50 or 5I, as the case may be, by means of four hollow rivets 52 in the manner shown, and formed in each bracket at each support is a hole 53 through which the lower end of the associated rubber block extends with some clearance. The side rails and crosspieces are secured to the shock absorbing supports by means of rivets 54 which pass through the rails and the crosspieces, and through the sleeves 49d, and each rivet is provided at its lower end with a'stop washer 55. The upper ends of the two rear rivets 54 are located in countersunk holes in the side rails and are made flush with the tops of the side rails for a purpose which will appear hereinafter.

As best seen in Figs. 2 and 4, the rear crosspiece 48 is bowed downwardly at its central portion and has secured thereto a little to the right of its center, as viewedin Fig. 2, a stop pin 55. The reason for this construction will be made clear presently.

The supporting framework in the form here shown comprises two U-shapedrstirrups 51 and 58 which surround the bottom and two sides of the operating mechanism, and which are secured at their upper ends to the operating mechanism by means of screws 59. The screws 59 extend through countersunk holes 60 in the stirrups and are screwed into threaded inserts 6I provided inthe opposite sides of the top plate 35.'`

The stirrups are secured together at their lower or horizontal portions by means of two laterally spaced tie bars 62 and 63 riveted to the undersides of the horizontal portions of the stirrups. The tie bars at their forward ends project beyond the forward stirrup 58 for a distance substantially equal to the width of the forwards crosspiece 41 of the track; and the projecting ends of the tie bars are rounded at their outer corners and are bent downwardly a slight amount for a purpose which will appear presently. Pivotally attached to the horizontal portion of the forward stirrup 58 midway between the tie bars 62 and 63 is a locking lever 64. This lever extends rearwardly in the same plane as.

the tie bars 62 and 63 to a point some distance to the rear of the rear stirrup 51, and is provided intermediate its ends with a double headed friction locking pin 65 so positioned that when the locking lever is moved to its locking position in which it is midway between the tie bars, the shank of the pin will just clear the rear stirrup 51 and the upper head of the pin will overlie with slight clearance the forward edge of the rear stirrup 51. The portion of the pin disposed below the locking lever cooperates with the downwardly bowed portion of the rear crosspiece 48 of the track in a manner which will be made clear presently.

With the mounting means constructed in the manner described the track assembly is secured in place in the casing l during assembly of the signal, and a supporting framework is secured to each operating mechanism. `When'it is desired to insert an operating mechanism into the casing, the light unit L is rst removed, and with the operating mechanism held in a position in which its rear end is elevated slightly, the forward stirrup is rested at the opposite ends of its horizontal portion on the two side rails 45 .and 46 and they mechanism is then slid forwardly until lthe forward stirrup engages the front crosspiece 41 of the track assembly. When the signal reaches thisposition, the locking lever is rotated to its extreme lefthand position, as viewed in Fig. 2, and the rear end of the signal is then lowered to the position in which the rear stirrup rests at the opposite ends of its horizontalA portion on the two side rails. The locking lever is next rotated to theright, as viewed in Fig. 2, to the position in which it engages the stop pins 56'., This rotation causes the locking pin to move to the position in which its upper head overlies the horizontal portion of the rear stirrup and its lower head underlies the rear crosspiece 48, and the parts are so proportioned that when the locking pin reaches this position, the downwardly bowed portion of the rear crosspiece will cause a frictional force to be exerted on the locking pin, which force is sufficient to hold it in its locking position in which it engages the pin 56. The spacing between the two tie bars 62 and 63 is such that they will just fit between the two side rails, and it will be seen, therefore, that the tie bars cooperate with the side rails to position the operating mechanism laterally in the casing l. The mechanism is positioned longitudinally in the casing I in the forward direction by engagement of the forward stirrup 58 with the forward crosspiece 41, and in the rear direction by engagement of the shank of the locking pin 65 with the `rear crosspiece 48. Vertical displacement of the mechanism at itsforward end is prevented by virtue of the fact that the forwardly extended portions of the tie bars underlie and engage the underside of the forward crosspiece, and vertical displacement of the mechanism at its rear end is prevented by engagement of the lower head of the locking pin with the underside of the rear crosspiece. The shock absorbing devices are so constructed that they allow a, small amount of motion of the operating mechanism, usually about in both the up and down direction. Due, however, to the fact that the area of the roundels is considerably larger than the area of the signal beam where it passes through the roundels this amount of movement is not sufficient to affect the signal beam. This amount of movement, however, is very effective in preventing the transmission of damaging vibration from the casing l to the operating mechanism.

After the operating mechanism has been placed in the signal casing in the marmer described, the light unit L may then be snapped in place.

When it is desired to remove the operating mechanism from the signal case, the procedure is just theopposite of that described above and will be obvious from the foregoing without further detailed description.'

One advantage of mounting means embodying my invention is that it is inexpensive to manufacture.

Another advantage of munting means embodying my invention is that it permits ready re- :"Lffg? tion cria-resilient track aesemblyisecured'wthin saidL casing, and a 'supporting framework'secured 'to saidmechanism and resting upon andremovably secured 'to said track for removably resilient- -l`y vsupporting saldmechanlsm withinvsaid casing. 3. In a light signal comprising a casing having an opening provided with a lens unit, a -light projecting unit xed withinsaid'casing'and capable ofV projectingl a' beam oi' lighty through'l a focal pointwhich coincides with the focal pointfot said lens unit, and an "perati'ng'mechanism foi-varying the color of the lightemitted by said signal including a plurality oi color filters which are VVselectively moved into said beam at the 4common focal point, lthe combination fof two spaced brack-v place!'x'i'ent opone-"operating 'mechanism `byy vani, :.,mer 4 ilfAlthogh Fhav fhereixr-shcwnand? describedv dnlyon'ef form Voi*A lig'htfsigri'al embodying my '1in- Vveritieraitis#understod''that various changes'and 5 Y YV-'modifications' may #be 'made therein within ythe 'l co'peof theappendediclaims"Without departing from" the spirit and sc'opef'of myv invention.V Y,bfi-raving' thus` described'fmy"invention, what I` *claim is: o f Y l0 l'In a signal -forv separately :projecting a `plu `-'--firality\of=beams'offditferent colorsfrom a single f'light'source including optical-parts' ifor concen- Eftrating" rthelightiilrom4 `said sourcev'into" a light -Wbeam'- and color'lters secured to and operated by"l 15 o 'anoperating mechanismj separate from said op- "ets Secured t0 'Sad Casing 9 trackfcomprisng Bide ucar-parts: and amused-tov be selectiveiymoved rails and-fro'ntandrear crosspiece'sfarranged in f byfsaid ,opera-ting mooha'ni-Sm intowthopath of rectangular "formation and supportedy at-their 5,;.g9lid-light` beamandfech having 'an area which endsin resilient supports'secured to' said bracknig-considerably largor'than' the area' ofthe. beam 2o ets, the rear crosspiece being bowed downwardly #where it passes through the filters, wnerebgf 11m- 'nd'provldedjwi'th larStop Pin, front and Tear-Stirfitedf movement of the operatingv mechanismrel- Pups :Secured at their' upper ends t0 Sad Operatianverssauercriticar-partswill notfvary the optical mg mechanism and resting @t their IOWGF'POMOHS y--ei'licrency ofthe sigaar the'combination 'of sup- '0n Said' Side rails" 'Sid"stim1ps'be1n8 Secured t0- porting mechanism for :Said operating mocha; 25 getherv by tici-bars which cooperate with saidsfide :i 1nismi' yincludingv a resilient track yassembly mountals to PositionLs-ayid mechaniSmlat-erauy Wlthm' ,mijn1 afpo'sitioni fixedwwth` resp-ect to .Said opt Sald Casing, Sald mechanism 'being DOSOIlBd alpprts Vmdasupportingframework secured forwardly in said casing 'by'engagement of said utowztheOperating 'mchanismf-and--resting .upon 'front stirrup with said `front Vcrosspi'ece, exten` --;oid wackassemblyv said 'mick assembly ooop i 30 sions on said tie bars underlying said front cross- I-'eratir'lgfwith` said supporting" framework to guide Plece toprevent Verticaldisplament ofthe for' i-ooidwoperating mechanismrmto Iposition and 'Said ward end ofsaid mechanism, a lockinglever piv- :supporting framework oemgprovidod 'Withmoans otally attached to said front stirriipfandextend- "f-Ioriremovably sec'ringitiin ai fixed' position with ing rearwardly Past Saidreal'. Stllup and Provid- A-frespet'toS-aid track AssemblyV Y35 ed with a double headed pinwhich` cooperates t 2,111n a-qighf, signal-comprising a casing havwith said rear crosspiece when said lever is-rofing anopening fprovided'with a lens unir xed to tated into engagement with `said stoppin to prenmuyagingr afalightaprojeoting 'umg fixed` within A Vvent rearward 'movement ofqsaid"mechanismy in -ffsaid 'casing and capable oflpojecting a beam of Sad'casing andalso *to prevent vertnicalndispla' c.,ight,through affocappomt-Whch coincides with* 4,0A ment of said mechanism, said" pin also cooperatwt-he focall pointof' saiddensunit', and anpperatl "ing With Sad'dOWnWaldly bWed Portion 0f Said fvinglmechanismforvaying'thecolorzof the'ljght rear crosspiece to frictionalLvfolock said lever in lemitted-,by Saidsignar including a plurality of the position nwhich it engages said stop pin. ycolorffllters which arerselectively' rno'ved into said 45 `WESLEY B, WELLS. 

